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def find_fraudulent_merchants_with_disputes(non_fraud_codes, fraud_codes, mcc_thresholds, merchant_mcc_map, min_charges, charges):
# Convert fraud codes and non-fraud codes into sets
non_fraud_codes = set(non_fraud_codes.split(','))
fraud_codes = set(fraud_codes.split(','))
# Parse the mcc_thresholds into a dictionary with percentages
mcc_dict = {}
for mcc in mcc_thresholds:
code, threshold = mcc.split(',')
mcc_dict[code] = float(threshold)
# Parse the merchant_mcc_map into a dictionary
merchant_dict = {}
for merchant in merchant_mcc_map:
account, mcc = merchant.split(',')
merchant_dict[account] = mcc
# Initialize counters for the number of transactions and fraudulent transactions per merchant
transaction_count = {}
fraudulent_count = {}
charge_map = {} # Keep track of charges to apply disputes later
# Parse charges and count transactions and fraudulent ones
for charge in charges:
parts = charge.split(',')
if parts[0] == 'DISPUTE':
charge_id = parts[1]
charge_map[charge_id]['disputed'] = True # Mark the transaction as disputed
else:
charge_type, charge_id, account_id, amount, code = parts
if account_id not in transaction_count:
transaction_count[account_id] = 0
fraudulent_count[account_id] = 0
transaction_count[account_id] += 1
is_fraudulent = code in fraud_codes
charge_map[charge_id] = {'account_id': account_id, 'is_fraudulent': is_fraudulent, 'disputed': False}
if is_fraudulent:
fraudulent_count[account_id] += 1
# Convert min_charges from string to int
min_charges = int(min_charges)
# Apply disputes: recalculate fraudulent counts for any disputed transactions
for charge_id, charge_info in charge_map.items():
if charge_info['disputed'] and charge_info['is_fraudulent']:
account_id = charge_info['account_id']
fraudulent_count[account_id] -= 1
# Determine which merchants are fraudulent based on percentage thresholds
fraudulent_merchants = []
for account_id in merchant_dict:
if transaction_count[account_id] >= min_charges:
mcc = merchant_dict[account_id]
threshold = mcc_dict.get(mcc, 1.0) # Get fraud threshold for the merchant's MCC (as a fraction)
fraud_percentage = fraudulent_count[account_id] / transaction_count[account_id] # Calculate fraud percentage
# Mark merchant if fraud percentage is equal to or greater than threshold
if fraud_percentage >= threshold:
fraudulent_merchants.append(account_id)
# Return the result as a lexicographically sorted comma-separated string
return ','.join(sorted(fraudulent_merchants))Editor is loading...
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